package util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;


import java.io.IOException;
import java.io.InputStream;

public class MybatisUtils {
    private static SqlSessionFactory factory;
    private static final ThreadLocal<SqlSession>THREAD_LOCAL=new ThreadLocal<>();

    static {
        try {
            InputStream is= Resources.getResourceAsStream("mybatis-config.xml");
            factory=new SqlSessionFactoryBuilder().build(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static <T> T getMapper(Class<T> clazz){
        SqlSession session=getSession();
        return session.getMapper(clazz);
    }

    public static SqlSession getSession(){
        SqlSession session=THREAD_LOCAL.get();
        if(session==null){
            session=factory.openSession();
            THREAD_LOCAL.set(session);
        }
        return session;
    }

    public static void close(SqlSession session){
        try {
            session.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void commit() {
        SqlSession session = getSession();
        session.commit();
        close(session);
    }

    public static void rollback(){
        SqlSession session=getSession();
        session.rollback();
        close(session);
    }

}
